Landfill leachate pretreatment process

The invention discloses a landfill leachate pretreatment process in which the landfill leachate is pretreated by adopting the following pretreatment device. The pretreatment device comprises a coagulation unit and a filter pressing unit, wherein the coagulation unit comprises an oxidation reaction chamber, a lime reaction chamber, a sodium hydroxide reaction chamber and a sodium carbonate reaction chamber which are communicated in sequence; the filter pressing unit comprises at least two filter presses, the filter presses are communicated with the sodium carbonate reaction chamber; landfill leachate enters the oxidation reaction chamber, the lime reaction chamber, the sodium hydroxide reaction chamber and the sodium carbonate reaction chamber in sequence for reaction and then enters the filter pressing unit, and the filter presses are fed in sequence, circulating in this way, only one filter press is used for feeding each time, and the obtained press filtrate is the pretreated leachate. According to the landf